U.S. patent application number 15/813771 was filed with the patent office on 2019-05-16 for track system for a vehicle.
The applicant listed for this patent is CAMSO INC.. Invention is credited to JEREMIE ZUCHOSKI.
Application Number | 20190144055 15/813771 |
Document ID | / |
Family ID | 66431740 |
Filed Date | 2019-05-16 |
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United States Patent
Application |
20190144055 |
Kind Code |
A1 |
ZUCHOSKI; JEREMIE |
May 16, 2019 |
TRACK SYSTEM FOR A VEHICLE
Abstract
A track system for a vehicle (e.g., an all-terrain vehicle
(ATV)) in which the track system is configured to enhance traction,
floatation, and/or other aspects of its performance, such as, for
example, to maintain proper contact with the ground (e.g., even if
it is cambered) and/or to better absorb shocks when it encounters
obstacles on the ground.
Inventors: |
ZUCHOSKI; JEREMIE;
(SHERBROOKE, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CAMSO INC. |
Magog |
|
CA |
|
|
Family ID: |
66431740 |
Appl. No.: |
15/813771 |
Filed: |
November 15, 2017 |
Current U.S.
Class: |
180/9.21 |
Current CPC
Class: |
B62D 55/104 20130101;
B62D 55/253 20130101; B62D 55/065 20130101; B62D 55/14 20130101;
B62D 55/084 20130101; B62D 55/10 20130101; B62D 55/12 20130101;
B62D 11/20 20130101; B62D 55/244 20130101 |
International
Class: |
B62D 55/084 20060101
B62D055/084; B62D 55/14 20060101 B62D055/14; B62D 55/10 20060101
B62D055/10; B62D 55/12 20060101 B62D055/12; B62D 55/24 20060101
B62D055/24; B62D 11/20 20060101 B62D011/20; B62D 55/065 20060101
B62D055/065; B62D 55/104 20060101 B62D055/104 |
Claims
1. A track system for a vehicle, the track system comprising: a
track comprising a ground-engaging outer surface for engaging the
ground and an inner surface opposite to the ground-engaging outer
surface; and a track-engaging assembly configured to move the track
around the track-engaging assembly; wherein an area of contact
between the track-engaging assembly and a bottom run of the track
spans less than half of a width of the track in a widthwise
direction of the track system at a cross-section of the
track-engaging assembly where the track-engaging assembly contacts
the bottom run of the track.
2. The track system of claim 1, wherein the area of contact between
the track-engaging assembly and the bottom run of the track spans
no more than 40% of the width of the track in the widthwise
direction of the track system at the cross-section of the
track-engaging assembly.
3. The track system of claim 1, wherein the area of contact between
the track-engaging assembly and the bottom run of the track spans
no more than 30% of the width of the track in the widthwise
direction of the track system at the cross-section of the
track-engaging assembly.
4. The track system of claim 1, wherein the area of contact between
the track-engaging assembly and the bottom run of the track spans
no more than 20% of the width of the track in the widthwise
direction of the track system at the cross-section of the
track-engaging assembly.
5. The track system of claim 1, wherein the area of contact between
the track-engaging assembly and the bottom run of the track spans
less than half of the width of the track in the widthwise direction
of the track system at every cross-section of the track-engaging
assembly where the track-engaging assembly contacts the bottom run
of the track.
6. The track system of claim 1, wherein the area of contact between
the track-engaging assembly and the bottom run of the track spans
no more than 40% of the width of the track in the widthwise
direction of the track system at every cross-section of the
track-engaging assembly where the track-engaging assembly contacts
the bottom run of the track.
7. The track system of claim 1, wherein the area of contact between
the track-engaging assembly and the bottom run of the track spans
no more than 30% of the width of the track in the widthwise
direction of the track system at every cross-section of the
track-engaging assembly where the track-engaging assembly contacts
the bottom run of the track.
8. The track system of claim 1, wherein the area of contact between
the track-engaging assembly and the bottom run of the track spans
no more than 20% of the width of the track in the widthwise
direction of the track system at every cross-section of the
track-engaging assembly where the track-engaging assembly contacts
the bottom run of the track.
9. The track system of claim 1, wherein the track-engaging assembly
comprises a drive wheel for driving the track and a plurality of
idler wheels contacting the bottom run of the track.
10. The track system of claim 9, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans less than half of the width of the track in the widthwise
direction of the track system at cross-sections of the
track-engaging assembly where respective ones of the idler wheels
contact the bottom run of the track.
11. The track system of claim 10, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans no more than 40% of the width of the track in the widthwise
direction of the track system at the cross-sections of the
track-engaging assembly where the respective ones of the idler
wheels contact the bottom run of the track.
12. The track system of claim 10, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans no more than 30% of the width of the track in the widthwise
direction of the track system at the cross-sections of the
track-engaging assembly where the respective ones of the idler
wheels contact the bottom run of the track.
13. The track system of claim 10, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans no more than 20% of the width of the track in the widthwise
direction of the track system at the cross-sections of the
track-engaging assembly where the respective ones of the idler
wheels contact the bottom run of the track.
14. The track system of claim 9, wherein: the track-engaging
assembly comprises a frame supporting the idler wheels; the frame
comprises a longitudinal base carrying the idler wheels; and the
area of contact between the track-engaging assembly and the bottom
run of the track is contained within the longitudinal base of the
frame of the track-engaging assembly in the widthwise direction of
the track system.
15. The track system of claim 9, wherein: the track-engaging
assembly comprises a frame supporting the idler wheels; the frame
comprises a longitudinal base carrying the idler wheels; and the
area of contact between the track-engaging assembly and the bottom
run of the track spans no more than a width of the longitudinal
base of the frame of the track-engaging assembly in the widthwise
direction of the track system.
16. The track system of claim 15, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans less than the width of the longitudinal base of the frame of
the track-engaging assembly in the widthwise direction of the track
system.
17. The track system of claim 15, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans less than three-quarters of the width of the longitudinal
base of the frame of the track-engaging assembly in the widthwise
direction of the track system.
18. The track system of claim 15, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans less than two-thirds of the width of the longitudinal base of
the frame of the track-engaging assembly in the widthwise direction
of the track system.
19. The track system of claim 15, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans less than half of the width of the longitudinal base of the
frame of the track-engaging assembly in the widthwise direction of
the track system.
20. The track system of claim 1, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
is continuous in the widthwise direction of the track system.
21. The track system of claim 1, wherein, at the cross-section of
the track-engaging assembly, the track-engaging assembly comprises
a track-engaging member engaging the bottom run of the track and is
free of contact with the bottom run of the track from the
track-engaging member to lateral edges of the track.
22. The track system of claim 21, wherein: the track-engaging
assembly comprises a drive wheel for driving the track and a
plurality of idler wheels contacting the bottom run of the track;
and the track-engaging member is a given one of the idler
wheels.
23. The track system of claim 9, wherein the idler wheels are
centrally disposed in the widthwise direction of the track system
such that each of the idler wheels overlaps a centerline of the
track that bisects the track in the widthwise direction of the
track.
24. The track system of claim 23, wherein the idler wheels are
arranged in a single line following the centerline of the track in
the longitudinal direction of the track system.
25. The track system of claim 9, wherein: the track-engaging
assembly comprises a frame supporting the idler wheels; the frame
comprises a longitudinal base carrying the idler wheels; the
longitudinal base of the frame of the track-engaging assembly
comprises a void; and a given one of the idler wheels is disposed
in the void.
26. The track system of claim 25, wherein: the void is a first
void; the given one of the idler wheels is a first one of the idler
wheels; the longitudinal base of the frame of the track-engaging
assembly comprises a second void spaced from the first void in the
longitudinal direction of the track system; and a second one of the
idler wheels is disposed in the second void.
27. The track system of claim 26, wherein: the first void is
located in a front region of the longitudinal base of the frame of
the track-engaging assembly; the first one of the idler wheels is a
leading idler wheel; the second void is located in a rear region of
the longitudinal base of the frame of the track-engaging assembly;
and the second one of the idler wheels is a trailing idler
wheel.
28. The track system of claim 26, wherein: the longitudinal base of
the frame of the track-engaging assembly comprises a third void
between the first void and the second void in the longitudinal
direction of the track system; and a third one of the idler wheels
is disposed in the third void.
29. The track system of claim 28, wherein: the first void is
located in a front region of the longitudinal base of the frame of
the track-engaging assembly; the first one of the idler wheels is a
leading idler wheel; the second void is located in a rear region of
the longitudinal base of the frame of the track-engaging assembly;
the second one of the idler wheels is a trailing idler wheel; the
third void is located in an intermediate region of the longitudinal
base of the frame of the track-engaging assembly; and the third one
of the idler wheels is a roller wheel.
30. The track system of claim 29, wherein: the roller wheel is a
first roller wheel; and a fourth one of the idler wheels is a
second roller wheel and is disposed in the third void.
31. The track system of claim 30, wherein the first roller wheel
and the second roller wheel are mounted together to pivot about a
pivot axis between the first roller wheel and the second roller
wheel in the longitudinal direction of the track system.
32. The track system of claim 9, wherein each of the idler wheels
is aligned with the drive wheel in the widthwise direction of the
track system.
33. The track system of claim 9, wherein each of the idler wheels
is narrower than the drive wheel in the widthwise direction of the
track system.
34. The track system of claim 1, wherein the track-engaging
assembly is configured such that every part of the track-engaging
assembly that contacts the bottom run of the track remains in
contact with the bottom run of the track even if the track system
is cambered.
35. The track system of claim 9, wherein the track-engaging
assembly is configured such that every idler wheel remains in
contact with the bottom run of the track even if the track system
is cambered.
36. The track system of claim 1, wherein: the track comprises
lateral portions extending from lateral extremities of the
track-engaging assembly to lateral edges of the track; and the
track-engaging assembly is configured to allow each of the lateral
portions of the track to flex inwardly and absorb a shock when the
track system encounters an obstacle on the ground.
37. The track system of claim 1, wherein: the cross-section of the
track-engaging assembly is a first cross-section of the
track-engaging assembly; and the area of contact between the
track-engaging assembly and the bottom run of the track at a second
cross-section of the track-engaging assembly where the
track-engaging assembly contacts the bottom run of the track is
wider in the widthwise direction of the track than the area of
contact between the track-engaging assembly and the bottom run of
the track at the first cross-section of the track-engaging
assembly.
38. The track system of claim 37, wherein: a ratio of (1) a
dimension of the area of contact between the track-engaging
assembly and the bottom run of the track in the widthwise direction
of the track system at the first cross-section of the
track-engaging assembly over (2) the dimension of the area of
contact between the track-engaging assembly and the bottom run of
the track at the second cross-section of the track-engaging
assembly is no more than 0.9.
39. The track system of claim 37, wherein: a ratio of (1) a
dimension of the area of contact between the track-engaging
assembly and the bottom run of the track in the widthwise direction
of the track system at the first cross-section of the
track-engaging assembly over (2) the dimension of the area of
contact between the track-engaging assembly and the bottom run of
the track at the second cross-section of the track-engaging
assembly is no more than 0.7.
40. The track system of claim 9, wherein: the cross-section of the
track-engaging assembly is a first cross-section of the
track-engaging assembly; a first one of the idler wheels is located
at the first cross-section of the track-engaging assembly; the area
of contact between the track-engaging assembly and the bottom run
of the track at a second cross-section of the track-engaging
assembly where the track-engaging assembly contacts the bottom run
of the track is wider in the widthwise direction of the track than
the area of contact between the track-engaging assembly and the
bottom run of the track at the first cross-section of the
track-engaging assembly; and a second one of the idler wheels and a
third one of the idler wheels are located at the second
cross-section of the track-engaging assembly and spaced from one
another in the widthwise direction of the track system.
41. The track system of claim 40, wherein: the track-engaging
assembly comprises a frame supporting the idler wheels; the frame
comprises a longitudinal base carrying the idler wheels; the first
one of the idler wheels is contained within the longitudinal base
of the frame of the track-engaging assembly in the widthwise
direction of the track system; and the second one of the idler
wheels and the third one of the idler wheels are respectively
located outside of the longitudinal base of the frame of the
track-engaging assembly and face outer lateral surfaces of the
longitudinal base of the frame of the track-engaging assembly.
42. The track system of claim 9, wherein: the track-engaging
assembly comprises a frame supporting the idler wheels; the frame
comprises a longitudinal base carrying the idler wheels; the idler
wheels include a leading idler wheel, a trailing idler wheel, and a
plurality of roller wheels located between the leading idler wheel
and the trailing idler wheel in the longitudinal direction of the
track system; a given one of the leading idler wheel and the
trailing idler wheel is contained within the longitudinal base of
the frame of the track-engaging assembly in the widthwise direction
of the track system; and a first one of the roller wheels and a
second one of the roller wheels are respectively located outside of
the longitudinal base of the frame of the track-engaging assembly
and face outer lateral surfaces of the longitudinal base of the
frame of the track-engaging assembly.
43. The track system of claim 9, wherein the track comprises a
plurality of wheel-contacting projections projecting from the inner
surface.
44. The track system of claim 43, wherein the wheel-contacting
projections include drive projections for engaging the drive wheel
to drive the track.
45. The track system of claim 1, wherein the track system is
mountable to the vehicle such that the track system is steerable by
a steering device of the vehicle to change an orientation of the
track system relative to a frame of the vehicle in order to turn
the vehicle.
46. The track system of claim 1, wherein the track system is
mountable to the vehicle in place of a ground-engaging wheel
comprising a tire.
47. The track system of claim 9, wherein: the idler wheels include
a leading idler wheel, a trailing idler wheel, and a plurality of
roller wheels located between the leading idler wheel and the
trailing idler wheel in the longitudinal direction of the track
system; and the bottom run of the track comprises a front segment
under the leading idler wheel, a rear segment under the trailing
idler wheel, and an intermediate segment under the roller wheels
and extending lower than a given one of the front segment and the
rear segment of the bottom run of the track.
48. The track system of claim 47, wherein the given one of the
front segment and the rear segment of the bottom run of the track
is the front segment of the bottom run of the track.
49. The track system of claim 48, wherein the intermediate segment
of the bottom run of the track extends lower than the rear segment
of the bottom run of the track.
50. The track system of claim 9, wherein: the idler wheels include
a leading idler wheel, a trailing idler wheel, and a plurality of
roller wheels located between the leading idler wheel and the
trailing idler wheel in the longitudinal direction of the track
system; and a bottom of the leading idler wheel is higher than a
bottom of a frontmost one of the roller wheels.
51. The track system of claim 50, wherein a bottom of the trailing
idler wheel is higher than a bottom of a rearmost one of the roller
wheels.
52. The track system of claim 9, wherein: the idler wheels include
a leading idler wheel, a trailing idler wheel, and a plurality of
roller wheels located between the leading idler wheel and the
trailing idler wheel in the longitudinal direction of the track
system; and a bottom of the leading idler wheel is higher than a
bottom of the trailing idler wheel.
53. The track system of claim 9, wherein: the idler wheels include
a leading idler wheel, a trailing idler wheel, and a plurality of
roller wheels located between the leading idler wheel and the
trailing idler wheel in the longitudinal direction of the track
system; and a distance between an axis of rotation of the drive
wheel and an axis of rotation of the leading idler wheel in the
longitudinal direction of the track system is different from a
distance between the axis of rotation of the drive wheel and an
axis of rotation of the trailing idler wheel in the longitudinal
direction of the track system.
54. The track system of claim 1, wherein the track-engaging
assembly is pivotable relative to a frame of the vehicle about an
axis of rotation parallel to the widthwise direction of the track
system.
55. The track system of claim 1, wherein the vehicle is an
all-terrain vehicle (ATV).
56. A track system for a vehicle, the track system comprising: a
track comprising a ground-engaging outer surface for engaging the
ground and an inner surface opposite to the ground-engaging outer
surface; and a track-engaging assembly configured to move the track
around the track-engaging assembly; wherein an area of contact
between the track-engaging assembly and a bottom run of the track
spans less than half of a width of the track in a widthwise
direction of the track system at every cross-section of the
track-engaging assembly where the track-engaging assembly contacts
the bottom run of the track.
57. A track system for a vehicle, the track system comprising: a
track comprising a ground-engaging outer surface for engaging the
ground and an inner surface opposite to the ground-engaging outer
surface; and a track-engaging assembly configured to move the track
around the track-engaging assembly, the track-engaging assembly
comprising a drive wheel for driving the track and a plurality of
idler wheels contacting a bottom run of the track; wherein an area
of contact between the track-engaging assembly and a bottom run of
the track spans less than half of a width of the track in a
widthwise direction of the track system at cross-sections of the
track-engaging assembly where respective ones of the idler wheels
contact the bottom run of the track.
58. The track system of claim 57, wherein the area of contact
between the track-engaging assembly and the bottom run of the track
spans less than half of the width of the track in the widthwise
direction of the track system at every cross-section of the
track-engaging assembly where an idler wheel contacts the bottom
run of the track.
59. A track system for a vehicle, the track system comprising: a
track comprising a ground-engaging outer surface for engaging the
ground and an inner surface opposite to the ground-engaging outer
surface; and a track-engaging assembly configured to move the track
around the track-engaging assembly, the track-engaging assembly
comprising a drive wheel for driving the track, a plurality of
idler wheels contacting a bottom run of the track, and a frame
supporting the idler wheels; the frame comprising a longitudinal
base carrying the idler wheels; wherein a given one of the idler
wheels is contained within the longitudinal base of the frame of
the track-engaging assembly in a widthwise direction of the track
system.
60. The track system of claim 59, wherein every idler wheel is
contained within the longitudinal base of the frame of the
track-engaging assembly in the widthwise direction of the track
system.
61. A track system for a vehicle, the track system comprising: a
track comprising a ground-engaging outer surface for engaging the
ground and an inner surface opposite to the ground-engaging outer
surface; and a track-engaging assembly configured to move the track
around the track-engaging assembly, the track-engaging assembly
comprising a drive wheel for driving the track and a plurality of
idler wheels contacting a bottom run of the track, the idler wheels
including a leading idler wheel and a trailing idler wheel spaced
from one another in a longitudinal direction of the track system;
wherein the leading idler wheel and the trailing idler wheel are
centrally disposed in a widthwise direction of the track system
such that each of the leading idler wheel and the trailing idler
wheel overlaps a centerline of the track that bisects the track in
the widthwise direction of the track.
62. The track system of claim 61, wherein: the idler wheels include
a plurality of roller wheels located between the leading idler
wheel and the trailing idler wheel in the longitudinal direction of
the track system; and the roller wheels are centrally disposed in
the widthwise direction of the track system such that each of the
roller wheels overlaps the centerline of the track.
63. A track system for a vehicle, the track system comprising: a
track comprising a ground-engaging outer surface for engaging the
ground and an inner surface opposite to the ground-engaging outer
surface; and a track-engaging assembly configured to move the track
around the track-engaging assembly, the track-engaging assembly
comprising a track-engaging member engaging a bottom run of the
track at a cross-section of the track-engaging assembly and is free
of contact with the bottom run of the track from the track-engaging
member to lateral edges of the track at the cross-section of the
track-engaging assembly.
64. A track system for a vehicle, the track system comprising: a
track comprising a ground-engaging outer surface for engaging the
ground and an inner surface opposite to the ground-engaging outer
surface; and a track-engaging assembly configured to move the track
around the track-engaging assembly; wherein the track-engaging
assembly is configured such that every part of the track-engaging
assembly that contacts a bottom run of the track remains in contact
with the bottom run of the track even if the track system is
cambered.
65. A track system for a vehicle, the track system comprising: a
track comprising a ground-engaging outer surface for engaging the
ground and an inner surface opposite to the ground-engaging outer
surface; and a track-engaging assembly configured to move the track
around the track-engaging assembly, the track-engaging assembly
comprising a drive wheel for driving the track and a plurality of
idler wheels contacting a bottom run of the track; wherein the
track-engaging assembly is configured such that every idler wheel
remains in contact with the bottom run of the track even if the
track system is cambered.
Description
FIELD
[0001] This disclosure relates generally to off-road vehicles
(e.g., all-terrain vehicles (ATVs), agricultural vehicles, etc.)
and, more particularly, to track systems for such vehicles.
BACKGROUND
[0002] Certain off-road vehicles may be equipped with track systems
which enhance their traction and/or floatation on soft, slippery
and/or irregular grounds (e.g., soil, mud, sand, ice, snow, etc.)
on which they operate.
[0003] For example, an all-terrain vehicle (ATV) may be equipped
with track systems in place of ground-engaging wheels with tires
for which it may have been originally designed. While this may help
for traction and/or floatation of the ATV, the track systems may
experience issues because they are different (e.g., in geometry,
size, structure, behavior, etc.) from the ground-engaging wheels
for which the ATV may have been originally designed. For instance,
the ATV may be set up so that its ground-engaging wheels are
cambered (e.g., have a positive or negative camber), but the track
systems may not account for this, which may detrimentally affect
performance of the track systems, such as by altering a "contact
patch" (i.e., an area of contact) of each track system with the
ground in ways that can be adverse to steerability and/or
manoeuvrability of the ATV.
[0004] Similar considerations may arise for track systems of other
types of off-road vehicles (e.g., agricultural vehicles, etc.) in
certain situations.
[0005] For these and other reasons, there is a need to improve
track systems for vehicles.
SUMMARY
[0006] According to various aspects, this disclosure relates to a
track system for a vehicle in which the track system is configured
to enhance traction, floatation, and/or other aspects of its
performance, such as, for example, to maintain proper contact with
the ground (e.g., even if it is cambered) and/or to better absorb
shocks when it encounters obstacles on the ground.
[0007] For example, according to an aspect, this disclosure relates
to a track system for a vehicle. The track system includes a track
including a ground-engaging outer surface for engaging the ground
and an inner surface opposite to the ground-engaging outer surface;
and a track-engaging assembly configured to move the track around
the track-engaging assembly. An area of contact between the
track-engaging assembly and a bottom run of the track spans less
than half of a width of the track in a widthwise direction of the
track system at a cross-section of the track-engaging assembly
where the track-engaging assembly contacts the bottom run of the
track.
[0008] According to another aspect, this disclosure relates to a
track system for a vehicle. The track system includes a track
including a ground-engaging outer surface for engaging the ground
and an inner surface opposite to the ground-engaging outer surface;
and a track-engaging assembly configured to move the track around
the track-engaging assembly. An area of contact between the
track-engaging assembly and a bottom run of the track spans less
than half of a width of the track in a widthwise direction of the
track system at every cross-section of the track-engaging assembly
where the track-engaging assembly contacts the bottom run of the
track.
[0009] According to another aspect, this disclosure relates to a
track system for a vehicle. The track system includes a track
including a ground-engaging outer surface for engaging the ground
and an inner surface opposite to the ground-engaging outer surface;
and a track-engaging assembly configured to move the track around
the track-engaging assembly. The track-engaging assembly includes a
drive wheel for driving the track and a plurality of idler wheels
contacting a bottom run of the track. An area of contact between
the track-engaging assembly and a bottom run of the track spans
less than half of a width of the track in a widthwise direction of
the track system at cross-sections of the track-engaging assembly
where respective ones of the idler wheels contact the bottom run of
the track.
[0010] According to another aspect, this disclosure relates to a
track system for a vehicle. The track system includes a track
including a ground-engaging outer surface for engaging the ground
and an inner surface opposite to the ground-engaging outer surface;
and a track-engaging assembly configured to move the track around
the track-engaging assembly. The track-engaging assembly includes a
drive wheel for driving the track, a plurality of idler wheels
contacting a bottom run of the track, and a frame supporting the
idler wheels. The frame includes a longitudinal base carrying the
idler wheels. A given one of the idler wheels is contained within
the longitudinal base of the frame of the track-engaging assembly
in a widthwise direction of the track system.
[0011] According to another aspect, this disclosure relates to a
track system for a vehicle. The track system includes a track
including a ground-engaging outer surface for engaging the ground
and an inner surface opposite to the ground-engaging outer surface;
and a track-engaging assembly configured to move the track around
the track-engaging assembly. The track-engaging assembly includes a
drive wheel for driving the track and a plurality of idler wheels
contacting a bottom run of the track. The idler wheels include a
leading idler wheel and a trailing idler wheel spaced from one
another in a longitudinal direction of the track system. The
leading idler wheel and the trailing idler wheel are centrally
disposed in a widthwise direction of the track system such that
each of the leading idler wheel and the trailing idler wheel
overlaps a centerline of the track that bisects the track in the
widthwise direction of the track.
[0012] According to another aspect, this disclosure relates to a
track system for a vehicle. The track system includes: a track
including a ground-engaging outer surface for engaging the ground
and an inner surface opposite to the ground-engaging outer surface;
and a track-engaging assembly configured to move the track around
the track-engaging assembly. The track-engaging assembly includes a
track-engaging member engaging a bottom run of the track at a
cross-section of the track-engaging assembly and is free of contact
with the bottom run of the track from the track-engaging member to
lateral edges of the track at the cross-section of the
track-engaging assembly.
[0013] According to another aspect, this disclosure relates to a
track system for a vehicle. The track system includes: a track
including a ground-engaging outer surface for engaging the ground
and an inner surface opposite to the ground-engaging outer surface;
and a track-engaging assembly configured to move the track around
the track-engaging assembly. The track-engaging assembly is
configured such that every part of the track-engaging assembly that
contacts a bottom run of the track remains in contact with the
bottom run of the track even if the track system is cambered.
[0014] According to another aspect, this disclosure relates to a
track system for a vehicle. The track system includes: a track
including a ground-engaging outer surface for engaging the ground
and an inner surface opposite to the ground-engaging outer surface;
and a track-engaging assembly configured to move the track around
the track-engaging assembly. The track-engaging assembly comprises
a drive wheel for driving the track and a plurality of idler wheels
contacting a bottom run of the track. The track-engaging assembly
is configured such that every idler wheel remains in contact with
the bottom run of the track even if the track system is
cambered.
[0015] These and other aspects of this disclosure will now become
apparent to those of ordinary skill in the art upon review of the
following description of embodiments in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A detailed description of embodiments is provided below, by
way of example only, with reference to the accompanying drawings,
in which:
[0017] FIGS. 1A and 1B show an example of an embodiment of an
all-terrain vehicle (ATV) comprising track systems;
[0018] FIGS. 2A and 2B show the ATV equipped with ground-engaging
wheels instead of the track systems;
[0019] FIGS. 3 and 4 respectively show perspective and side views
of a track system of the track systems;
[0020] FIGS. 5 and 6 respectively show perspective and side views
of the track system without its track;
[0021] FIGS. 7 and 8 show perspective views of a segment of the
track of the track system, which depict features of an inner side
and a ground-engaging outer side of the track;
[0022] FIG. 9 shows a side view of the track of the track
system;
[0023] FIG. 10 shows a plan view of the inner side of the track of
the track system;
[0024] FIG. 11 shows a plan view of the outer side of the track of
the track system;
[0025] FIGS. 12 and 13 show cross-sectional views of the track of
the track system;
[0026] FIGS. 14 and 15 show cross-sectional views of a variant of
the track of the track system;
[0027] FIGS. 16 to 20 show views of a segment of a variant of the
track;
[0028] FIGS. 21A and 21B show end views of the track system without
its track, without camber and with camber;
[0029] FIGS. 22A and 22B show end views of a conventional track
system without its track, without camber and with camber;
[0030] FIG. 23 shows a leading idler wheel and a segment of a track
of a conventional track system;
[0031] FIG. 24 shows a leading idler wheel and a segment of the
track of the track system;
[0032] FIGS. 25 and 26 show the leading idler wheel and the segment
of the track of the track system with and without presence of an
obstacle;
[0033] FIG. 27 shows an example of another embodiment of the track
system;
[0034] FIGS. 28 and 29 show views of the track system of FIG.
27;
[0035] FIG. 30 shows a view of the track system of FIG. 27 without
its track;
[0036] FIGS. 31A and 31C show a cross-sectional view of the leading
idler wheel in contact with the track according to a various
embodiment of the track system;
[0037] FIGS. 32 and 33 show a cross-sectional view of the leading
idler wheel in contact with the track and of roller wheels in
contact with the track according to a various embodiment of the
track system;
[0038] FIG. 34 shows an example of an embodiment of a track system
of a snowmobile;
[0039] FIG. 35 shows an example of an embodiment of a track system
of a snow bike; and
[0040] FIG. 36 shows the snow bike of FIG. 35 when it is converted
to be equipped with front and rear wheels.
[0041] It is to be expressly understood that the description and
drawings are only for the purpose of illustrating certain
embodiments, are an aid for understanding, and are not
limiting.
DETAILED DESCRIPTION OF EMBODIMENTS
[0042] FIGS. 1A and 1B show an example of an embodiment of a
tracked vehicle 10 comprising a plurality of track systems
16.sub.1-16.sub.4. In this embodiment, the vehicle 10 is an
all-terrain vehicle (ATV), which is a small open vehicle designed
to travel off-road on a variety of terrains, including roadless
rugged terrain, for recreational, utility and/or other
purposes.
[0043] In this embodiment, the ATV 10 comprises a frame 11, a
powertrain 12, a steering system 17, a suspension 19, the track
systems 16.sub.1-16.sub.4, a seat 18, and a user interface 20,
which enable a user of the ATV to ride the ATV 10 on the ground.
The ATV 10 has a longitudinal direction, a widthwise direction, and
a height direction.
[0044] As further discussed later, in this embodiment, each of the
track systems 16.sub.1-16.sub.4 is configured to enhance traction,
floatation, and/or other aspects of its performance, including to
maintain proper contact with the ground (e.g., even if it cambered)
and/or to better absorb shocks when it encounters obstacles on the
ground.
[0045] The powertrain 12 is configured for generating motive power
and transmitting motive power to the track systems
16.sub.1-16.sub.4 to propel the ATV 10 on the ground. To that end,
the powertrain 12 comprises a prime mover 14, which is a source of
motive power that comprises one or more motors. For example, in
this embodiment, the prime mover 14 comprises an internal
combustion engine. In other embodiments, the prime mover 14 may
comprise another type of motor (e.g., an electric motor) or a
combination of different types of motor (e.g., an internal
combustion engine and an electric motor). The prime mover 14 is in
a driving relationship with one or more of the track systems
16.sub.1-16.sub.4. That is, the powertrain 12 transmits motive
power generated by the prime mover 14 to one or more of the track
systems 16.sub.1-16.sub.4 (e.g., via a transmission and/or a
differential) in order to drive (i.e., impart motion to) these one
or more of the track systems 16.sub.1-16.sub.2.
[0046] The steering system 17 is configured to enable the user to
steer the ATV 10 on the ground. To that end, the steering system 17
comprises a steering device 13 that is operable by the user to
direct the ATV 10 along a desired course on the ground. In this
embodiment, the steering device 13 comprises handlebars. The
steering device 13 may comprise a steering wheel or any other
steering component that can be operated by the user to steer the
ATV 10 in other embodiments. The steering system 17 responds to the
user interacting with the steering device 13 by turning some of the
track systems 16.sub.1-16.sub.4 to change their orientation
relative to the frame 11 of the ATV 10 in order to cause the ATV 10
to move in a desired direction. In this example, front ones of the
track systems 16.sub.1-16.sub.4 are steerable (i.e., turnable) in
response to input of the user at the steering device 13 to change
their orientation relative to the frame 11 of the ATV 10 in order
to steer the ATV 10 on the ground. More particularly, in this
example, each of the front ones of the track systems
16.sub.1-16.sub.4 is pivotable about a steering axis 29 of the ATV
10 in response to input of the user at the steering device 10 in
order to steer the ATV 10 on the ground. Rear ones of the track
systems 16.sub.1-16.sub.4 are not turned relative to the frame 11
of the ATV 10 by the steering system 17.
[0047] The suspension 19 is connected between the frame 11 and the
track systems 16.sub.1-16.sub.4 to allow relative motion between
the frame 11 and the track systems 16.sub.1-16.sub.4 as the ATV 10
travels on the ground. The suspension 19 enhances handling of the
ATV 10 on the ground by absorbing shocks and helping to maintain
traction between the track systems 16.sub.1-16.sub.4 and the
ground. The suspension 19 may comprise an arrangement of springs
and dampers. A spring may be a coil spring, a leaf spring, a gas
spring (e.g., an air spring), or any other elastic object used to
store mechanical energy. A damper (also sometimes referred to as a
"shock absorber") may be a fluidic damper (e.g., a pneumatic
damper, a hydraulic damper, etc.), a magnetic damper, or any other
object which absorbs or dissipates kinetic energy to decrease
oscillations. In some cases, a single device may itself constitute
both a spring and a damper (e.g., a hydropneumatic, hydrolastic, or
hydragas suspension device).
[0048] In this embodiment, the seat 18 is a straddle seat and the
ATV 10 is usable by a single person such that the seat 18
accommodates only that person driving the ATV 10. In other
embodiments, the seat 18 may be another type of seat, and/or the
ATV 10 may be usable by two individuals, namely one person driving
the ATV 10 and a passenger, such that the seat 18 may accommodate
both of these individuals (e.g., behind one another or
side-by-side) or the ATV 10 may comprise an additional seat for the
passenger. For example, in other embodiments, the ATV 10 may be a
side-by-side ATV, sometimes referred to as a "utility terrain
vehicle" or "utility task vehicle" (UTV).
[0049] The user interface 20 allows the user to interact with the
ATV 10. More particularly, the user interface 20 comprises an
accelerator, a brake control, and the steering device 13 that are
operated by the user to control motion of the ATV 10 on the ground.
The user interface 20 also comprises an instrument panel (e.g., a
dashboard) which provides indicators (e.g., a speedometer
indicator, a tachometer indicator, etc.) to convey information to
the user.
[0050] The track systems 16.sub.1-16.sub.4 engage the ground to
provide traction to the ATV 10. More particularly, in this example,
the front ones of the track systems 16.sub.1-16.sub.4 provide front
traction to the ATV 10 while the rear ones of the track systems
16.sub.1-16.sub.4 provide rear traction to the ATV 10.
[0051] In this embodiment, as shown in FIGS. 2A and 2B, each of the
track systems 16.sub.1-16.sub.4 is mounted in place of a respective
one of a plurality of ground-engaging wheels 15.sub.1-15.sub.4
having tires with which the ATV 10 may equipped. Basically, in this
embodiment, the track systems 16.sub.1-16.sub.4 may be used to
convert the ATV 10 from a wheeled vehicle into a tracked vehicle,
thereby enhancing its traction and floatation on the ground.
[0052] With additional reference to FIGS. 3 to 6, in this
embodiment, each track system 16.sub.i comprises a track 41 and a
track-engaging assembly 22 to move the track 41 around the
track-engaging assembly 22. In this example, the track-engaging
assembly 22 comprises a frame 44 and a plurality of
track-contacting wheels which includes a drive wheel 42 and a
plurality of idler wheels 50.sub.1-50.sub.4. The track system
16.sub.i has a front longitudinal end 57 and a rear longitudinal
end 59 that define a length of the track system 16.sub.i. A width
of the track system 16.sub.i is defined by a width W.sub.T of the
track 41. An envelope of the track system 16.sub.i is defined by a
length of the track 41. The track system 16.sub.i has a
longitudinal direction, a widthwise direction (i.e., a lateral
direction), and a height direction.
[0053] The track 41 engages the ground to provide traction to the
ATV 10. The length of the track 41 allows the track 41 to be
mounted around the track-engaging assembly 22. In view of its
closed configuration without ends that allows it to be disposed and
moved around the track-engaging assembly 22, the track 41 can be
referred to as an "endless" track. Referring additionally to FIGS.
7 to 11, the track 41 comprises an inner side 45 facing the wheels
42, 50.sub.1-50.sub.4 and a ground-engaging outer side 47 opposite
the inner side 45 for engaging the ground. Lateral edges 63.sub.1,
63.sub.2 of the track 41 define the track's width W.sub.T. The
track 41 has a top run 65 which extends between the longitudinal
ends 57, 59 of the track system 16.sub.i and over the wheels 42,
50.sub.1-50.sub.4 and a bottom run 66 which extends between the
longitudinal ends 57, 59 of the track system 16.sub.i and under the
wheels 42, 50.sub.1-50.sub.4. The bottom run 66 of the track 41
defines an area of contact 58 of the track 41 with the ground which
generates traction and bears a majority of a load on the track
system 16.sub.i, and which will be referred to as a "contact patch"
of the track 41 with the ground. The track 41 has a longitudinal
direction, a widthwise direction (i.e., a lateral direction), and a
thickness direction.
[0054] The track 41 is elastomeric in that it comprises elastomeric
material allowing it to flex around the wheels 42,
50.sub.1-50.sub.4. The elastomeric material of the track 41 can
include any polymeric material with suitable elasticity. In this
embodiment, the elastomeric material includes rubber. Various
rubber compounds may be used and, in some cases, different rubber
compounds may be present in different areas of the track 41. In
other embodiments, the elastomeric material of the track 41 may
include another elastomer in addition to or instead of rubber
(e.g., polyurethane elastomer). The track 41 can be molded into
shape in a mold by a molding process during which its elastomeric
material is cured.
[0055] More particularly, the track 41 comprises an elastomeric
belt-shaped body 36 underlying its inner side 45 and its
ground-engaging outer side 47. In view of its underlying nature,
the body 36 can be referred to as a "carcass". The carcass 36
comprises elastomeric material 37 which allows the track 41 to flex
around the wheels 42, 50.sub.1-50.sub.4.
[0056] As shown in FIG. 12, in some embodiments, the carcass 36 may
comprise a plurality of reinforcements 68.sub.1-68.sub.R (e.g.,
reinforcing layers) embedded in its elastomeric material 37. One
example of a reinforcement 68.sub.i is a layer of reinforcing
cables 38.sub.1-38.sub.C that are adjacent and generally parallel
to one another. For instance, the reinforcing cables
38.sub.1-38.sub.C may extend in the longitudinal direction of the
track 41 to enhance strength in tension of the track 41 along its
longitudinal direction. In some cases, a reinforcing cable may be a
cord or wire rope including a plurality of strands or wires. In
other cases, a reinforcing cable may be another type of cable and
may be made of any material suitably flexible longitudinally (e.g.,
fibers or wires of metal, plastic or composite material). Another
example of a reinforcement 68.sub.i is a layer of reinforcing
fabric 40. Reinforcing fabric comprises pliable material made
usually by weaving, felting, knitting, interlacing, or otherwise
crossing natural or synthetic elongated fabric elements, such as
fibers, filaments, strands and/or others, such that at least some
of the elongated fabric elements extend transversally to the
longitudinal direction of the track 41 to have a reinforcing effect
transversally to the longitudinal direction of the track 41. For
instance, a layer of reinforcing fabric may comprise a ply of
reinforcing woven fibers (e.g., nylon fibers or other synthetic
fibers). Various other types of reinforcements may be provided in
the carcass 36 in other embodiments.
[0057] The carcass 36 may be molded into shape in the track's
molding process during which its elastomeric material 37 is cured.
For example, in some embodiments, layers of elastomeric material
providing the elastomeric material 37 of the carcass 36, the
reinforcing cables 38.sub.1-38.sub.C and the layer of reinforcing
fabric 40 may be placed into the mold and consolidated during
molding.
[0058] In this embodiment, the inner side 45 of the track 41
comprises an inner surface 32 of the carcass 36 and a plurality of
wheel-contacting projections 48.sub.1-48.sub.N that project from
the inner surface 32 to contact at least some of the wheels 42,
50.sub.1-50.sub.4 and that are used to do at least one of driving
(i.e., imparting motion to) the track 41 and guiding the track 41.
In that sense, the wheel-contacting projections 48.sub.1-48.sub.N
can be referred to as "drive/guide projections", meaning that each
drive/guide projection is used to do at least one of driving the
track 41 and guiding the track 41. Also, such drive/guide
projections are sometimes referred to as "drive/guide lugs" and
will thus be referred to as such herein. More particularly, in this
embodiment, the drive/guide lugs 48.sub.1-48.sub.N interact with
the drive wheel 42 in order to cause the track 41 to be driven, and
also interact with the idler wheels 50.sub.1-50.sub.4 in order to
guide the track 41 as it is driven by the drive wheel 42. The
drive/guide lugs 48.sub.1-48.sub.N are thus used to both drive the
track 41 and guide the track 41 in this embodiment.
[0059] The drive/guide lugs 48.sub.1-48.sub.N are spaced apart
along the longitudinal direction of the track 41. In this case, the
drive/guide lugs 48.sub.1-48.sub.N are arranged in a plurality of
rows that are spaced apart along the widthwise direction of the
track 41. The drive/guide lugs 48.sub.1-48.sub.N may be arranged in
other manners in other embodiments (e.g., a single row or more than
two rows). Each of the drive/guide lugs 48.sub.1-48.sub.N is an
elastomeric drive/guide lug in that it comprises elastomeric
material 67. The drive/guide lugs 48.sub.1-48.sub.N can be provided
and connected to the carcass 36 in the mold during the track's
molding process.
[0060] The ground-engaging outer side 47 of the track 41 comprises
a ground-engaging outer surface 31 of the carcass 36 and a
plurality of traction projections 61.sub.1-61.sub.M that project
from the outer surface 31 and engage and may penetrate into the
ground to enhance traction. The traction projections
61.sub.1-61.sub.M, which can sometimes be referred to as "traction
lugs" or "traction profiles", are spaced apart in the longitudinal
direction of the track system 16.sub.i. The ground-engaging outer
side 47 comprises a plurality of traction-projection-free areas
71.sub.1-71.sub.F (i.e., areas free of traction projections)
between successive ones of the traction projections
61.sub.1-61.sub.M. In this example, each of the traction
projections 61.sub.1-61.sub.M is an elastomeric traction projection
in that it comprises elastomeric material 69. The traction
projections 61.sub.1-61.sub.M can be provided and connected to the
carcass 36 in the mold during the track's molding process.
[0061] Each traction projection 61.sub.i extends transversally to
the longitudinal direction of the track 41. That is, the traction
projection 61.sub.i has a longitudinal axis 54 extending
transversally to the longitudinal direction of the track 41. In
this example, the longitudinal axis 54 of the traction projection
61.sub.i is substantially parallel to the widthwise direction of
the track 41. In other examples, the longitudinal axis 54 of the
traction projection 61.sub.i may be transversal to the longitudinal
direction of the track 41 without being parallel to the widthwise
direction of the track 41. The traction projections
61.sub.1-61.sub.M may be configured in various other ways in other
embodiments.
[0062] In this example, the carcass 36 has a thickness T.sub.c
which is relatively small. The thickness T.sub.c of the carcass 36
is measured from the inner surface 32 to the ground-engaging outer
surface 31 of the carcass 36 between longitudinally-adjacent ones
of the traction projections 61.sub.1-61.sub.M. For example, in some
embodiments, the thickness T.sub.c of the carcass 36 may be no more
than 0.250 inches, in some cases no more than 0.240 inches, in some
cases no more than 0.230 inches, in some cases no more than 0.220
inches, in some cases no more than 0.210 inches, in some cases no
more than 0.200 inches, and in some cases even less (e.g., 0.180 or
0.170 inches). The thickness T.sub.c of the carcass 36 may have any
other suitable value in other embodiments.
[0063] In this embodiment, as shown in FIGS. 12 and 13, the track
41 is free of transversal stiffening rods embedded in its
elastomeric material. That is, the track 41 does not comprise
transversal stiffening rods embedded in its elastomeric material
and extending transversally to its longitudinal direction. FIGS. 14
and 15 shows a variant in which the track 41 may comprise
transversal stiffening rods 53.sub.1-53.sub.M embedded in its
elastomeric material and extending transversally to its
longitudinal direction in other embodiments. This absence of
transversal stiffening rods in some embodiments, such as shown in
FIGS. 12 and 13, makes the track 41 more flexible in its widthwise
direction than if the track 41 had the transversal stiffening rods
53.sub.1-53.sub.M but was otherwise identical.
[0064] FIGS. 16 to 20 show an example of another embodiment of the
track 41 which comprises bent lateral edge portions 64.sub.1,
64.sub.2 adjacent its lateral edges 63.sub.1, 63.sub.2 to
facilitate steering of the track system 16.sub.i on the ground, by
making the contact patch 58 smaller. For instance, in some
embodiments, this may be used for the front ones of the track
systems 16.sub.1-16.sub.4. More particularly, the carcass 36 of the
track 41 of the track system 16.sub.i is bent inwardly proximate
the lateral edges 63.sub.1, 63.sub.2 of the track 41 such that its
inner surface 32 and ground-engaging outer surface 31 are bent
inwardly.
[0065] The track 41 may be constructed in various other ways in
other embodiments. For example, in some embodiments, the track 41
may comprise a plurality of parts (e.g., rubber sections)
interconnected to one another in a closed configuration, the track
41 may have recesses or holes that interact with the drive wheel 42
in order to cause the track 41 to be driven (e.g., in which case
the drive/guide lugs 48.sub.1-48.sub.N may be used only to guide
the track 41 without being used to drive the track 41), and/or the
ground-engaging outer side 47 of the track 41 may comprise various
patterns of traction projections.
[0066] The drive wheel 42 is rotatable about an axis of rotation 49
for driving the track 41 in response to rotation of an axle 21 of
the ATV. In this example, the axis of rotation 49 corresponds to an
axis of rotation 79 of the axle 21 of the ATV 10. More
particularly, in this example, the drive wheel 42 has a hub which
is mounted to the axle 21 of the ATV 10 such that power generated
by the prime mover 14 and delivered over the powertrain 12 of the
ATV 10 rotates the axle 21, which rotates the drive wheel 42, which
imparts motion of the track 41. In this embodiment in which the
track system 16.sub.i is mounted where a ground-engaging wheel
15.sub.i could otherwise be mounted, the axle 21 of the ATV 10 is
capable of rotating the drive wheel 42 of the track system 16.sub.i
or the ground-engaging wheel 15.sub.i.
[0067] In this embodiment, the drive wheel 42 comprises a drive
sprocket engaging the drive/guide lugs 48.sub.1-48.sub.N of the
inner side 45 of the track 41 in order to drive the track 41. In
this case, the drive sprocket 42 comprises a plurality of teeth
46.sub.1-46.sub.T distributed circumferentially along its rim to
define a plurality of lug-receiving spaces therebetween that
receive the drive/guide lugs 48.sub.1-48.sub.N of the track 41. The
drive wheel 42 may be configured in various other ways in other
embodiments. For example, in embodiments where the track 41
comprises recesses or holes, the drive wheel 42 may have teeth that
enter these recesses or holes in order to drive the track 41. As
yet another example, in some embodiments, the drive wheel 42 may
frictionally engage the inner side 45 of the track 41 in order to
frictionally drive the track 41.
[0068] The idler wheels 50.sub.1-50.sub.4 are not driven by power
supplied by the prime mover 14, but are rather used to do at least
one of supporting part of the weight of the ATV 10 on the ground
via the track 41, guiding the track 41 as it is driven by the drive
wheel 42, and tensioning the track 41. More particularly, in this
embodiment, the idler wheels 50.sub.1, 50.sub.4 are respectively a
front idler wheel (a leading idler wheel) and a rear idler wheel (a
trailing idler wheel) that maintain the track 41 in tension, and
can help to support part of the weight of the ATV 10 on the ground
via the track 41. The idler wheels 50.sub.2, 50.sub.3 are roller
wheels that roll on the inner side 45 of the track 41 along the
bottom run 66 of the track 41 to apply the bottom run 66 on the
ground. The idler wheels 50.sub.1-50.sub.4 move on an idler wheel
path 55 of the inner surface 32 of the carcass 36 of the track 41.
The idler wheel path 55 extends between respective ones of the
drive/guide lugs 48.sub.1-48.sub.N to allow these lugs to guide
motion of the track 41. The idler wheels 50.sub.1-50.sub.4 may be
arranged in other configurations and/or the track system 16.sub.i
may comprise more or less idler wheels in other embodiments.
[0069] In this embodiment, the bottom run 66 of the track 41 has a
geometry configured to help traction and maneuverability of the
track system 16.sub.i. More particularly, in this embodiment, the
front idler wheel 50.sub.1 is adjacent to the front longitudinal
end 57 of the track system 16.sub.i-, the rear idler wheel 50.sub.4
is adjacent to the rear longitudinal end 59 of the track system
16.sub.i, and the roller wheels 50.sub.2-50.sub.3 are located
between the front idler wheel 50.sub.1 and the rear idler wheel
50.sub.4 in the longitudinal direction of the track system
16.sub.i, such that the bottom run 66 of the track 41 comprises a
front segment 105 under the front idler wheel 50.sub.i, a rear
segment 109 under the rear idler wheel 50.sub.4, and an
intermediate segment 107 under the roller wheels 50.sub.2-50.sub.3
and extending lower than a given one of the front segment 105 and
the rear segment 109 of the bottom run 66 of the track 44. In this
example, the intermediate segment 107 of the bottom run 66 of the
track 41 extends lower than each of the front segment 105 and the
rear segment 109 of the bottom run 66 of the track 44. Also, in
this example, the intermediate segment 107 of the bottom run 66 of
the track 41 is generally flat and parallel to the ground between
the roller wheels 50.sub.2-50.sub.3.
[0070] As the front and rear idler wheels 50.sub.1 and 50.sub.4
maintain the track 41 in tension and may, at least at rest, not
apply the track to the ground, the front and rear idler wheels
50.sub.1 and 50.sub.4 may be elevated relative to the ground. For
example, in this embodiment, a bottom 101 of the front idler wheel
50.sub.1 is higher than a bottom 102 of a frontmost one of the
roller wheels 50.sub.2-50.sub.3 and bottom 104 of a rearmost one of
the roller wheels 50.sub.2-50.sub.3. Also, in this embodiment, the
bottom 101 of the front idler wheel 50.sub.1 is higher than a
bottom 104 of the rear idler wheels 50.sub.4.
[0071] Thus, in this example, a height relative to the ground
H.sub.i of the front idler wheel 50.sub.1 may be greater than a
height relative to the ground H.sub.i of the rear idler wheel
50.sub.4. To manage the traction and the maneuverability of each of
the track systems 16.sub.1-16.sub.4, as the front ones of the track
systems 16.sub.1-16.sub.4 may require a different amount of
traction and/or a different degree of maneuverability than the rear
ones of the track systems 16.sub.1-16.sub.4, their respective
geometry may differ.
[0072] In this embodiment, a distance between the axis of rotation
49 of the drive wheel 42 and an axis of rotation 60.sub.1 of the
front idler wheel 50.sub.1 in the longitudinal direction of the
track system 16.sub.i is different from a distance between the axis
of rotation 49 of the drive wheel 42 and an axis of rotation
60.sub.4 of the rear idler wheel 50.sub.4 in the longitudinal
direction of the track system 16.sub.i. In this example, the roller
wheels 50.sub.2-50.sub.3 of the front ones of the track systems
16.sub.1-16.sub.4 may be closer one to another than the roller
wheels 50.sub.2-50.sub.3 of the rear ones of the track systems
16.sub.1-16.sub.4. Also, in this example, for the front ones of the
track systems 16.sub.1-16.sub.4, the roller wheels
50.sub.2-50.sub.3 may be located closer the rear idler wheel
50.sub.4 than to the front idler wheel 50.sub.1, while for the rear
ones of the track systems 16.sub.1-16.sub.4, the roller wheels
50.sub.2-50.sub.3 may be closer to the front idler wheel 50.sub.1
than to the rear idler wheel 50.sub.4.
[0073] The frame 44 supports components of the track system
16.sub.i, including the idler wheels 50.sub.1-50.sub.4. More
particularly, in this embodiment, the front and rear idler wheels
50.sub.1, 50.sub.4 are respectively mounted to the frame 44 in a
front longitudinal end region of the frame 44 proximate the front
longitudinal end 57 of the track system 16.sub.i and in a rear
longitudinal end region of the frame 44 proximate the rear
longitudinal end 59 of the track system 16.sub.i. The roller wheels
50.sub.2, 50.sub.3 are mounted to the frame 44 in a central region
of the frame 44 between the front idler wheel 50.sub.1 and the rear
idler wheel 50.sub.4. Each of the roller wheels 50.sub.2, 50.sub.3
may be rotatably mounted directly to the frame 44 or may be
rotatably mounted to a link which is pivotally mounted to the frame
44 to which is rotatably mounted an adjacent one of the roller
wheels 50.sub.2, 50.sub.2, thus forming a "tandem".
[0074] In this embodiment, the frame 44 comprises a longitudinal
base 90 that is elongated in the longitudinal direction of the
track system 16.sub.i and carries the idler wheels
50.sub.1-50.sub.4 and an upper part 64 that extends upwardly from
the longitudinal base 90. In this example, the upper part 64 of the
frame 44 comprises arms 43.sub.1, 43.sub.2 that converge upwardly
from the longitudinal base 90.
[0075] The frame 44 is supported at a support area 39. More
specifically, in this case, the frame 44 is supported by the axle
21 of the ATV 10 to which is coupled the drive wheel 42, such that
the support area 39 is intersected by the axis of rotation 49 of
the drive wheel 42.
[0076] In this embodiment, the frame 44 is pivotable about a pivot
axis 51 to facilitate motion of the track system 16.sub.i on uneven
terrain and enhance its traction on the ground. More particularly,
in this embodiment, the pivot axis 51 corresponds to the axis of
rotation 49 of the drive wheel 42 and the frame 44 can pivot about
the axle of the ATV 10 to which the drive wheel 42 is coupled. In
other embodiments, the pivot axis 51 of the frame 44 may be located
elsewhere (e.g., lower) than the axis of rotation 49 of the drive
wheel 42. In yet other embodiments, the frame 44 may not be
pivotable.
[0077] Also, in this embodiment, the track system 16.sub.i
comprises an anti-rotation connector 52 to limit a pivoting
movement of the track system 16.sub.i relative to the frame 11 of
the ATV 10. In this example, the anti-rotation connector 52
comprises a spring and a damper and is connected between the frame
44 of the track system 16.sub.i and the frame 11 of the ATV 10
(e.g., via one or more mounting brackets and/or fasteners).
[0078] With additional reference to FIGS. 21A and 21B, in this
embodiment, the track-engaging assembly 22 is configured to engage
the bottom run 66 of the track 41 narrowly at certain locations as
this may help to enhance performance of the track system 16.sub.i.
For example, this may help to maintain the contact patch 58 of the
track 41 with the ground, even if the track system 16.sub.i is
cambered (e.g., a ground-engaging wheel 15.sub.i replaced by the
track system 16.sub.i had a camber, i.e., a positive or negative
camber, that is inherited by the track system 16.sub.i). This may
also help for shock absorption when the track 41 encounters an
obstacle on the ground (e.g., a rock, debris, an abrupt change in
ground level, etc.).
[0079] An area of contact 70 between the track-engaging assembly 22
and the bottom run 66 of the track 41 is thus narrow in the
widthwise direction of the track system 16.sub.i at one or more
cross-sections of the track-engaging assembly 22 where the
track-engaging assembly 22 contacts the bottom run 66 of the track
41. These one or more cross-sections of the track-engaging assembly
22 where it contacts the bottom run 66 of the track 41 are normal
to the longitudinal direction of the track system 16.sub.i and will
be referred to as one or more "track-contacting" cross-sections of
the track-engaging assembly 22. The area of contact 70 between the
track-engaging assembly 22 and the bottom run 66 of the track 41
encompasses every part of the track-engaging assembly 22 that
contacts the bottom run 66 of the track 41. In this example, the
area of contact 70 between the track-engaging assembly 22 and the
bottom run 66 of the track 41 thus encompasses an area of contact
between each of the idler wheels 50.sub.1-50.sub.4 and the bottom
run 66 of the track 41.
[0080] In this embodiment, the area of contact 70 between the
track-engaging assembly 22 and the bottom run 66 of the track 41 is
narrow in the widthwise direction of the track system 16.sub.i at
track-contacting cross-sections 71.sub.1-71.sub.4 of the
track-engaging assembly 22 where the idler wheels 50.sub.1-50.sub.4
contact the bottom run 66 of the track 41. In this example, the
area of contact 70 between the track-engaging assembly 22 and the
bottom run 66 of the track 41 is narrow in the widthwise direction
of the track system 16.sub.i at every track-contacting
cross-section (i.e., at all track-contacting cross-sections) of the
track-engaging assembly 22.
[0081] More particularly, in this embodiment, at every
track-contacting cross-section, including each of the
track-contacting cross-sections 71.sub.1-71.sub.4, of the
track-engaging assembly 22, the area of contact 70 between the
track-engaging assembly 22 and the bottom run 66 of the track 41
spans less than half, in some cases no more than 40%, in some cases
no more than 30%, and in some cases no more than 20% of the width
W.sub.T of the track 41 in the widthwise direction of the track
system 16.sub.i. That is, a dimension C.sub.T of the area of
contact 70 between the track-engaging assembly 22 and the bottom
run 66 of the track 41 in the widthwise direction of the track
system 16.sub.i at every track-contacting cross-section of the
track-engaging assembly 22 is less than half, in some cases no more
than 40%, in some cases no more than 30%, and in some cases no more
than 20% of the width W.sub.T of the track 41.
[0082] Also, in this embodiment, at every track-contacting
cross-section, including each of the track-contacting
cross-sections 71.sub.1-71.sub.4, of the track-engaging assembly
22, the area of contact 70 between the track-engaging assembly 22
and the bottom run 66 of the track 41 is contained within (i.e., is
not located beyond) the longitudinal base 90 of the frame 44 of the
track system 16.sub.i in the widthwise direction of the track
system 16.sub.i. More particularly, in this embodiment, the area of
contact 70 between the track-engaging assembly 22 and the bottom
run 66 of the track 41 spans no more than a width W.sub.F of the
longitudinal base 90 of the frame 44 of the track system 16.sub.i
in the widthwise direction of the track system 16.sub.i. In this
example, the area of contact 70 between the track-engaging assembly
22 and the bottom run 66 of the track 41 spans less than the width
W.sub.F of the longitudinal base 90 of the frame 44 of the track
system 16.sub.i in the widthwise direction of the track system
16.sub.i. For instance, in some embodiments, the area of contact 70
between the track-engaging assembly 22 and the bottom run 66 of the
track 41 may span less than three-quarters, in some cases less than
two-thirds, and in some cases less than half of the width W.sub.F
of the longitudinal base 90 of the frame 44 of the track system
16.sub.i in the widthwise direction of the track system
16.sub.i.
[0083] Furthermore, in this embodiment, at every track-contacting
cross-section, including each of the track-contacting
cross-sections 71.sub.1-71.sub.4, of the track-engaging assembly
22, the area of contact 70 between the track-engaging assembly 22
and the bottom run 66 of the track 41 is continuous (i.e.,
uninterrupted) in the widthwise direction of the track system
16.sub.i. That is, at track-contacting every cross-section of the
track-engaging assembly 22, the area of contact 70 between the
track-engaging assembly 22 and the bottom run 66 of the track 41 is
defined by a single part of the track-engaging assembly 22 that
continuously extends in contact with the bottom run 66 of the track
41 without interruption in the widthwise direction of the track
system 16.sub.i.
[0084] Thus, in this embodiment, at every track-contacting
cross-section, including each of the track-contacting
cross-sections 71.sub.1-71.sub.4, of the track-engaging assembly
22, the track-engaging assembly 22 comprises a track-engaging
member 72 engaging the bottom run 66 of the track 41 and is free of
contact with (i.e., does not contact) the bottom run 66 of the
track 41 from the track-engaging member 72 to the lateral edges
63.sub.1, 63.sub.2 of the track 41. For instance, in this
embodiment, the track-engaging member 72 is a given one of the
idler wheels 50.sub.1-50.sub.4. The track-engaging assembly 22 is
free of (i.e., has no) track-engaging structure spaced from the
given one of the idler wheels 50.sub.1-50.sub.4 in the widthwise
direction of the track system 16.sub.i and contacting the bottom
run 66 of the track 41.
[0085] More particularly, in this embodiment, the idler wheels
50.sub.1-50.sub.4 are centrally disposed in the widthwise direction
of the track system 16.sub.i. Each of the idler wheels
50.sub.1-50.sub.4 overlaps a centerline 75 of the track 41 that
bisects the track's width W.sub.T. The idler wheels
50.sub.1-50.sub.4 are arranged in a single line following the
centerline 75 of the track 1 in the longitudinal direction of the
track system 16.sub.i. Also, the idler wheels 50.sub.1-50.sub.4 are
aligned with the drive wheel 42 in the widthwise direction of the
track system 16.sub.i.
[0086] In this embodiment, the idler wheels 50.sub.1-50.sub.4 are
contained within the longitudinal base 90 of the frame 44 of the
track-engaging assembly 22 in the widthwise direction of the track
system 16.sub.i. More particularly, in this embodiment, the
longitudinal base 90 of the frame 44 comprises voids
93.sub.1-93.sub.v for containing respective ones of the idler
wheels 50.sub.1-50.sub.4. In some examples, each of the voids
93.sub.1-93.sub.4 may contain only a single one of the idler wheels
50.sub.1-50.sub.4. In other examples, a given one of the voids
93.sub.1-93.sub.v may contain at least two of the idler wheels
50.sub.1-50.sub.4. The voids 93.sub.1-93.sub.v are aligned with the
drive wheel 42 in the widthwise direction of the track system
16.sub.i. In other embodiments, the longitudinal base 90 of the
frame 44 of the track system 16.sub.i may comprise only a single
void containing all of the idler wheels 50.sub.1-50.sub.4. In some
cases, this may allow the track system 16.sub.i to be reduced in
width, thus allowing a lower width to the vehicle 10.
[0087] As shown in FIGS. 21A and 21B, in this embodiment, the
track-engaging assembly 22 is configured such that every part of
the track-engaging assembly 22 that contacts the bottom run 66 of
the track 41 remains in contact with the bottom run 66 of the track
41 even if the track system 16.sub.i is cambered. More
particularly, in this embodiment, the track-engaging assembly 22 is
configured such that every one of the idler wheels
50.sub.1-50.sub.4 remains in contact with the bottom run 66 of the
track 41, even if the track system 16.sub.i is cambered. This may
help to maintain the contact patch 58 of the track 41 with the
ground and thus enhance traction. For example, in this embodiment,
the track system 16.sub.i is cambered because a ground-engaging
wheel 15.sub.i replaced by the track system 16.sub.i had a camber,
i.e., a positive or negative camber, so that, when the track system
16.sub.i is mounted in place of the ground-engaging wheel 15.sub.i,
the camber is inherited by the track system 16.sub.i.
[0088] For instance, in some embodiments, every one of the idler
wheels 50.sub.1-50.sub.4 may remain in contact with the bottom run
66 of the track 41 even if the track system 16.sub.i is cambered at
a camber angle .alpha. of at least 5.degree., in some cases at
least 10.degree., in some cases at least 15.degree., in some cases
at least 20.degree., and in some cases even more.
[0089] This contrasts with a conventional track system with a wide
area of contact between its track-engaging assembly and a bottom
run of its track, an example of which is shown in FIGS. 22A and
22B, where some of its idler wheels and/or other parts of its
track-engaging assembly would not contact the bottom run of its
track when the conventional track system is cambered.
[0090] The area of contact 70 between the track-engaging assembly
22 and the bottom run 66 of the track 41 being narrow in the
widthwise direction of the track system 16.sub.i may also be useful
for steerability and/or other aspects of maneuverability. For
example, in some embodiments, this may be useful when the track
system 16.sub.i is steered about the steering axis 29. For
instance, in some cases, a stabilization of the vehicle 10 may be
improved such as by having the areas of contact 70 for each of the
track systems 16.sub.1-16.sub.4 that are more distant in the
widthwise direction of the vehicle 10 relative to a longitudinal
centerline 81 of the vehicle 10. Additionally or alternatively, in
some cases, mechanical stresses in parts of the track system
16.sub.i and/or the vehicle 10, such as the suspension 19, may be
diminished.
[0091] In this embodiment, with additional reference to FIGS. 23,
24 and 26, the area of contact 70 between the track-engaging
assembly 22 and the bottom run 66 of the track 41 being narrow in
the widthwise direction of the track system 16.sub.i may help for
shock absorption when the track 41 encounters an obstacle 80 on the
ground (e.g., a rock, debris, an abrupt change in ground level,
etc.).
[0092] More particularly, in this embodiment, this reduces a
potential for the track-engaging assembly 22 to impact the obstacle
80 on the ground when the track system 16.sub.i encounters the
obstacle 80 on the ground, and allows a given one of lateral
portions 83.sub.1, 83.sub.2 of the track 41 that extend from
lateral extremities of the area of contact 70 of 85.sub.1, 85.sub.2
between the track-engaging assembly 22 and the bottom run 66 of the
track 41 to the lateral edges 63.sub.1, 63.sub.2 of the track 41 to
flex inwardly and absorb a shock from encountering the obstacle 80
on the ground.
[0093] For instance, the track system 16.sub.i comprises a stiffer
(i.e., more rigid) ground-engaging portion 96 having a width
W.sub.R where the track system 16.sub.i is more exposed to stress
occasioned by the obstacle 80 on the ground. The width W.sub.R of
the stiffer ground-engaging portion 96 of the track system 16.sub.i
may be less than that of a conventional track system comprising
rows of idler wheels that are laterally spaced apart, an example of
which is shown in FIG. 25, such that a narrower extent of the
stiffer ground-engaging portion 96 of the track system 16.sub.i
diminishes a risk that the obstacle 80 is encountered at the
stiffer ground-engaging portion 96 of the track system 16.sub.i and
rather increases a likelihood that the obstacle 80 is encountered
at either one of lateral portions 83.sub.1, 83.sub.2 of the track
41, which may help for shock absorption by deformation of that
impacted one of the lateral portions 83.sub.1, 83.sub.2 of the
track 41 which is substantially free to bend or otherwise deform as
it is uncontacted by the track-engaging assembly 22.
[0094] The track system 16.sub.i may be implemented in various
other ways in other embodiments.
[0095] For example, with additional reference to FIGS. 27 to 30, in
some embodiments, the area of contact 70 between the track-engaging
assembly 22 and the bottom run 66 of the track 41 may be narrow in
the widthwise direction of the track system 16.sub.i at some but
not all track-contacting cross-sections of the track-engaging
assembly 22, such as at one or more of but not all of the
track-contacting cross-sections 71.sub.1-71.sub.4 of the
track-engaging assembly 22 where the idler wheels 50.sub.1-50.sub.4
contact the bottom run 66 of the track 41.
[0096] In this embodiment, the track-engaging assembly 22 comprises
roller wheels 50.sub.2, 50.sub.3, 50.sub.5, 50.sub.6 and the area
of contact 70 between the track-engaging assembly 22 and the bottom
run 66 of the track 41 at each of the track-contacting
cross-sections 71.sub.1, 71.sub.4 of the track-engaging assembly 22
where a respective one of the front and rear idler wheels 50.sub.1,
50.sub.4 contacts the bottom run 66 of the track 41 is narrow as
discussed above in respect of FIGS. 21A and 21B, whereas the area
of contact 70 between the track-engaging assembly 22 and the bottom
run 66 of the track 41 at each of the track-contacting
cross-sections 71.sub.2, 71.sub.3 of the track-engaging assembly 22
where respective ones of the roller wheels 50.sub.2, 50.sub.3,
50.sub.5, 50.sub.6 contacts the bottom run 66 of the track 41 is
wider.
[0097] As best seen in FIGS. 32 and 33, in this embodiment, a ratio
of (1) the dimension C.sub.T of the area of contact 70 between the
track-engaging assembly 22 and the bottom run 66 of the track 41 in
the widthwise direction of the track system 16.sub.i at each of the
track-contacting cross-sections 71.sub.1, 71.sub.4 of the
track-engaging assembly 22 where a respective one of the front and
rear idler wheels 50.sub.1, 50.sub.4 contacts the bottom run 66 of
the track 41 over (2) the dimension C.sub.T of the area of contact
70 between the track-engaging assembly 22 and the bottom run 66 of
the track 41 at each of the track-contacting cross-sections
71.sub.2, 71.sub.3 of the track-engaging assembly 22 where
respective ones of the roller wheels 50.sub.2, 50.sub.3, 50.sub.5,
50.sub.6 contacts the bottom run 66 of the track 41 is no more than
0.9, in some cases no more than 0.8, in some cases no more than
0.7, and in some cases even less.
[0098] In this embodiment, the longitudinal base 90 of the frame 44
comprises the voids 93.sub.1, 93.sub.2 configured to house the
leading idler wheel 50.sub.1 and the trailing idler wheel 50.sub.4,
whereas the roller wheels 50.sub.2, 50.sub.3, 50.sub.5, 50.sub.6
are not housed in a void of the frame 44, but rather located
outside of the longitudinal base 90 of the frame 44 and face outer
lateral surfaces 98.sub.1, 98.sub.2 of the longitudinal base 90 of
the frame 44.
[0099] In some examples, an attachment 95 between each of the
roller wheels 50.sub.2, 50.sub.3, 50.sub.5, 50.sub.6 and the
longitudinal base 90 of the frame 44 may be rigid such as to
prevent each pair of the roller wheels 50.sub.2, 50.sub.3,
50.sub.5, 50.sub.6 to rotate relative to the frame 44 of the track
system 16.sub.i. In other examples, the attachment 95 between each
of the roller wheels 50.sub.2, 50.sub.3, 50.sub.5, 50.sub.6 and the
longitudinal base 90 of the frame may be flexible such as to allow
each pair of the roller wheels 50.sub.2, 50.sub.3, 50.sub.5,
50.sub.6 to rotate relative to the frame 44 of the track system
16.sub.i to emulate certain advantages discussed above. In yet
other examples, the attachment 95 between each of the roller wheels
50.sub.2, 50.sub.3, 50.sub.5, 50.sub.6 and the longitudinal base 90
of the frame may be rigid such as to prevent each pair of the
roller wheels 50.sub.2, 50.sub.3, 50.sub.5, 50.sub.6 to rotate
relative to the frame 44 of the track system 16.sub.i, but a
material of the roller wheels 50.sub.2, 50.sub.3, 50.sub.5,
50.sub.6, and/or a geometry of the roller wheels 50.sub.2,
50.sub.3, 50.sub.5, 50.sub.6 combined with a geometry of the inner
side 45 of the track 41 may be such that certain advantages
discussed above are replicated.
[0100] For example, with additional reference to FIGS. 31A to 31B,
the inner surface 32 may comprise grooves 82.sub.1,82.sub.2
themselves comprising rolling surfaces 84.sub.1-84.sub.2 extending
longitudinally along the track 41 and the roller wheels 50.sub.2,
50.sub.3, 50.sub.5, 50.sub.6 may comprise a rolling surface 86 that
is curved is such a way that, when there the track system 16.sub.i
is cambered, the roller wheels 50.sub.2, 50.sub.3, 50.sub.5,
50.sub.6 may be in contact with the rolling surfaces
84.sub.1-84.sub.2 when the camber angle .alpha. is less than a
certain value (e.g., 5.degree., 10.degree., 15.degree. or
20.degree.), but at least one of the roller wheels 50.sub.2,
50.sub.3, 50.sub.5, 50.sub.6 may be not be in contact with the
rolling surfaces 84.sub.1-84.sub.2 when the camber angle .alpha. is
more than that certain value.
[0101] While in this embodiment the track system 16.sub.i is part
of the ATV 10, in other embodiments, a track system constructed
according to principles discussed herein may be used as part of
other types of tracked vehicles.
[0102] For example, in some embodiments, as shown in FIG. 34, a
track system 616 comprising a track 641 constructed according to
principles discussed herein may be used as part of a snowmobile
610.
[0103] As another example, in some embodiments, as shown in FIGS.
35 and 36, a track system 716 comprising a track 741 constructed
according to principles discussed herein may be used as part of a
snow bike 710. The snow bike 710 is a motorcycle equipped with a
ski system 717 mounted in place of a front wheel 702 of the
motorcycle and the track system 716 mounted in place of a rear
wheel 704 of the motorcycle. In this example, the track system 716
also replaces a rear suspension unit (e.g., a shock absorber and a
swing arm) of the motorcycle. Basically, the track system 716
converts the motorcycle into a tracked vehicle for travelling on
snow.
[0104] The ATV 10, the snowmobile 610 and the snow bike 710
considered above are examples of recreational vehicles. While they
can be used for recreational purposes, such recreational vehicles
may also be used for utility purposes in some cases.
[0105] Also, while these examples pertain to recreational vehicles,
a track system comprising a track constructed according to
principles discussed herein may be used as part of tracked vehicles
other than recreational ones (e.g., agricultural vehicles,
construction vehicles, military vehicles, and other off-road
vehicles).
[0106] Certain additional elements that may be needed for operation
of some embodiments have not been described or illustrated as they
are assumed to be within the purview of those of ordinary skill in
the art. Moreover, certain embodiments may be free of, may lack
and/or may function without any element that is not specifically
disclosed herein.
[0107] Any feature of any embodiment discussed herein may be
combined with any feature of any other embodiment discussed herein
in some examples of implementation.
[0108] Although various embodiments and examples have been
presented, this was for purposes of description but is not
limiting. Various modifications and enhancements will become
apparent to those of ordinary skill in the art.
* * * * *